The ionic volume and surface area of the anion and cat'on are very important and fundamental properties of ionic liquids (ILs) which are widely used to predict the properties of IL systems. In this study, ionic volumes and surface areas for 249 ions were calculated, and thus, a database was established. Based on the database, two prediction models (each containing only one correction coefficient) for the molar volume of 126 ILs were developed using COSMO and van der Waals volumes. In addition, the densities of the 126 ILs were calculated by using the equation rho = M/V. The average absolute relative deviations of the predicted molar volume and density models were less than 3.5%, indicating the excellent precision of our models. Therefore, it can be concluded that the ionic volume and surface area database established in this work was reliable and could be extended to predict physicochemical properties of more than 10,000 ILs.